The Mission
by Korazan
Summary: [ONE-SHOT] Vongola Nono wants the Tenth Generation to take care of a mission. Tsuna has no idea what it is about. [R27]


**This is a short, simple something that's come to me a while back. I've sat on the idea for a long time, then, today, while reading over my notes, I stumbled on it and said: well, this has to be short. So I've written it :P Sorry for any mistake!**

 **SUMMARY:** [ONE-SHOT] Vongola Nono wants the Tenth Generation to take care of a mission. Tsuna has no idea what it is about. [R27]

 **WARNINGS:**

\- Short, simple, with many time-skips, maybe a bit confusing at the beginning;

\- Light shounen-ai, R27.

\- Adult!Reborn.

 **Words: 3349.**

 **Enjoy!**

* * *

 **The Mission**

* * *

Tsuna blinked. "I… can't read the contents?"

"No, Tsunayoshi." Vongola Nono kindly smiled at him, standing at the other side of the brunette's desk. "It's a mission that you can know about only after it's been completed. Assign it to your most trusted ones, they should know how to go about it on their own."

He swallowed, unsure. "As you wish, Timoteo."

"Thank you, Tsunayoshi. Consider this as my last request to Vongola." He nodded at him, leaving his office right after.

Decimo sighed, massaging his forehead. He twirled the envelope in his hand, frowning. He should really let his Guardians go on this without knowing the risks? Over-protective as he may seem, he cared about them too much to just do that, but… This was a request from Nono, something he could hardly ignore.

Tsuna took his phone and texted Hayato to come in his office. The Storm was knocking at his door in less than a minute. That made the brunette smile before allowing him in.

"Tenth, you called?"

Even if still the ever-following puppy always defending Tsuna whenever and for whatever, Hayato had piped down a lot through the years since the Inheritance Ceremony. It was a good change and a signal he had matured, which he couldn't help but be proud of.

"Yes, this." Tsuna lifted the hand with the envelope and his Storm strode through the little boudoir to take it with a firm hand. "It's a request from Nono. I can't read the contents, so open it and judge if it's something dangerous. Honestly, Hayato."

The silver-haired male nodded and slowly did as told. Tsuna observed his eyes dart from one side of the unfolded page to the other, the other's brows knitting in deep thought.

"It's not dangerous, Decimo." The serious tone as well as the thoughtful expression relaxed Tsuna impossibly, because his Storm never lied when like that. "Not for the one doing the mission, anyway." The brunette blinked, confused, and frowned. "But it's not something you should worry about, Tenth." Hayato grinned cheekily and folded the paper back into the envelope. "Leave it to me, I won't fail you!"

That said, his Guardian bowed, turned and left.

Tsuna could only wonder what the mission was about for Hayato to give him such a fond and soft look.

* * *

 _No._

 _No._

 _Nope._

 _Fuck no._

 _What the hell? That one's absurd._

 _No._

 _Fucking hell, no!_

 _No._

 _Double no._

 _Where should I go, the other face of the planet?_

 _Oh God, better bleach that one from my mind._

 _No._

 _What the fuck do you even wear?!_

 _No._

 _No._

 _Nope._

 _Fuck no._

 _This is insane, look at that!_

 _For fuck's sake, over my corpse… Not even._

 _No._

 _No…_

 _Unworthy._

 _No._

 _Weak._

 _N.O._

 _Jesus Christ! No!_

 _…_

 _I should try another country._

* * *

"… I'm sorry, I didn't catch that."

"I failed."

The voice, muffled by the carpet in front of his desk on which Hayato was kneeling dogeza-style, barely reached Tsuna's ears. He couldn't believe it.

His Storm Guardian, the one who, out of them all, had a record of successful and safely completed mission… had failed it. The request from Nono. After _four_ _whole months_.

"I'm unfit to be your right-hand-man! Please, forgive me, Decimo!"

Tsuna shook his head and stood to swiftly go by his friend's side, crouching down a bit. "Hayato, please, stand up." He slowly and unsurely did as told, not daring to look up. "Don't worry about it, ok? It just means that mission was not good for your mindset." He smiled, patting his hair, and the other finally looked up at him… like a lost puppy. "Can you call Takeshi for me? Maybe he'll find another way, who knows?"

Suddenly hopeful – which was a strange thing given he'd named his Rain – Hayato nodded eagerly and strode out of the office, closing the door softly. Tsuna blinked, once more confused. Usually, his Storm would bristle at the mere thought that the 'baseball freak' could do better than him. The brunette took a deep breath and eyed the open envelope. His curiosity had just increased, what with Hayato failing and _willing_ to let Takeshi try.

He lifted it off his desk and sat at one of the dark red sofa of the boudoir. His Rain knocked at door shortly after, not waiting for permission to enter. His usual smirk was a bit perturbed, maybe because of Hayato's strange behaviour, but his happiness at seeing his Boss was unmistakable.

"Hey, Tsuna!" He went up to the brunette, sitting on the opposite couch. "What's up?"

Decimo smiled, happy himself. "Good morning, Takeshi. How was your day?"

"Trained with Hibari, ahah!" He grinned. "Yours?"

"… Strange." He pursed his lips and passed him the envelope. "Nono visited me some time ago to request this mission done. I'm not allowed to read the contents and… Hayato has reported this a failure moments ago."

Takeshi blinked, grin falling as if a leaf off a branch in autumn. "That's…"

"Unheard of, yes." Tsuna nodded. "Read it and tell me if you want to try."

The taller male assumed a serious expression, taking the paper and unfolding it. If possible, his features got even more focused, which happened only during a fight or if someone angered him.

"I see… Well, Hayato is too strict for this." He looked up with a soft smile. "Don't worry, Tsuna, I'll try my best."

And his Rain, too, was off.

Tsuna returned to his paperwork with a sigh.

* * *

 _Well, ahah, no._

 _Oh, no._

 _No, that's… no._

 _Hayato must have had an aneurism._

 _What's that?! No!_

 _This is hard…_

 _Maybe I'm worse than Hayato…_

 _No way._

 _That's… No words._

 _And this? Might wo–no._

 _Weak…_

 _Choices, choices…_

* * *

"Sorry, Tsuna, I failed." Takeshi scratched his cheek sheepishly and chuckled without true humour. "Too hard for me. Maybe the others will be luckier. Uhm… I'll go call Lambo. He has good eyes."

The brunette could only blink in utter loss. What the hell… It's been two months this time. What was that mission about for not only his Storm but also his Rain to _fail_ it? Both, like, seriously? And Takeshi thought Lambo could… Hayato was smart while the swordsman had keen eyes… Last time he checked, the Bovino didn't have that good gaze… Just, what was this all about?

"Tsu-nii?"

He shook his head and smiled at his little brother. "Yes, Lambo, come in please."

The mop of afro hair had diminished during the years, turning into gel-coated curly hair. "What happened? Take-nii told me you wanted to see me." He seemed curious, but also wary, cute green eyes searching his frame for anything out of the ordinary.

"Actually…" He began, giving him the envelope. "A request from Nono, I can't read it. Takeshi and Hayato have reported it a failure." Lambo was not good at hiding his reaction, so he openly gaped. Tsuna chuckled. "Read it and tell me if you want to give it a try. It's summer break, fortunately."

Green eyes slowly narrowed as every word was read and digested. It was peculiar. His curiosity peaked even more.

"Leave it to me, Tsu-nii. Take-nii is right, I have good eyes for this."

That said, Lambo left the room just as Reborn was opening the door. The shorter male eyed the hitman critically before narrowing his eyes and leaving without a word. Tsuna felt spooked, Lambo had never done that before, and at the World's Greatest Hitman! He was scared of him!

"… What was that about?"

Tsuna looked up at his tutor, refusing to blush at the attention, and shook his head. "He's going on a mission… One Nono has tasked us, but I don't know anything about it. He has asked me to leave it to my most trusted ones."

"Why the cow brat?"

"Hayato and Takeshi have failed it." Reborn barely blinked in stupor, sitting down in front of Tsuna. "Takeshi has reported to me just now and then told me Lambo was a better choice because… He has 'good eyes'."

The hitman hummed and they fell silent. The brunette returned to his paperwork with a sigh, again. His Intuition was not warning him, so… He would only be the usual protective Boss and see.

* * *

 _Let's see… not this._

 _Too flashy._

 _Too exuberant._

 _Too flowery._

 _Too smelly._

 _Too open._

 _Too idiot._

 _Too uncaring._

 _Too much._

 _I have to change location, though…_

* * *

"I failed, Tsu-nii. I'll go call Ryo-nii. Wait for a bit."

The open envelope left on his desk felt ominous, for once. Tsuna gazed over Reborn, that was sipping his coffee while sitting on a couch, and swallowed. More than spooked, he was starting to feel irritated. What had his Guardians running around without even completing it? Three of them now and Lambo had taken three more months to return empty-handed.

"Tsunaaa! Extreeeme! What do you need me for?!"

The brunette thanked Lambo for having left the door open as it was still in one piece, thankfully. "For a mission, Ryohei. Here." He lifted the paper and gave it to the boxer. "Read it – I can't – and tell me if you want to do it."

Tsuna waited. Reborn carefully studied the Sun's expression as he read the paper. Ryohei changed completely, from the usually laid back stance to a readier one, serious for once.

"Ok, leave it to me." The Sun left the room, only an echo reaching them: "To the extreeeme!"

The Boss was officially at a loss. Ok, Hana had made the male calm down a bit, but that… that was uncharacteristic. The Sun Arcobaleno sipped some more of his coffee, thoughtful.

* * *

 _No to the extreeeeme!_

 _Extreeeemely no!_

 _Not extreeeme enough!_

* * *

Ryohei came back after a week. "I extreeeemely failed!" And disappeared through the destroyed door.

Ok. Ok.

… Ok.

He refused to think this through anymore.

"Tsunayoshi."

"Boss."

"Mukuro, Nagi…" Tsuna took a deep breath, knowing the paper was already being analysed by both his Mists. "I don't know what that's about, but… do you think you could do it?"

The young woman looked up at him with a soft smile as Mukuro just frowned. "We'll see."

In a swirl of white smoke, they disappeared. "This is becoming impossible."

"You still have Hibari."

"I… I have a feeling he wouldn't be interested, Reborn."

"Try."

Tsuna sighed. "Okay."

* * *

 _Nagi-chan, I see no one._

 _We have to search more, Mukuro-sama._

 _Fine…_

 _Until, you want to volunteer?_

 _Kufufufu…_

* * *

"We're sorry, Boss."

"Don't worry, Nagi-chan. At worst, I'll take care of it myself… Where's Mukuro?"

"Sulking."

… He didn't want to know. "Thanks… I'm happy you didn't scare people like you always do."

"What will you do, Boss?"

Tsuna thought about it, gazed over Reborn and sighed, standing with the envelope in his hand. "I'll ask Kyouya."

Nagi nodded. The brunette left the office alone and made his way to the basement, where his Cloud was most probably training while biting to death new recruits. He stopped to call Takeshi, that happily fell into steps.

"So, Hibari?"

Tsuna nodded, staying silent. The basement was unscathed, for once. The first wide room was filled with unconscious bodies. His Cloud was watching them with a shaking head. The grey eyes snapped to them as Decimo strode to him. Without a word, he lifted the envelope and let Kyouya take it.

"I don't know the contents." He explained as the other read the paper. "The others have all failed. Do you want to have a go?" His Cloud silently looked at him with piercing eyes. "Takeshi will take care of this."

After what seemed an eternity, he slowly nodded and pocketed the folded paper. With his cape fluttering, the young man waked away. However, he suddenly stopped and turned to them to say few words.

"A carnivore, omnivore."

And left.

Tsuna blinked, not knowing what to get out of that. Normally, he understood Hibareese quite well. He looked at Takeshi, but found him looking at Kyouya with narrowed eyes.

* * *

 _…_

 _…_

 _…_

 _Herbivores…_

 _…_

 _…_

 _…_

 _…_

 _Herbivores._

 _…_

 _…_

 _..._

 _…_

 _…_

 _Everywhere._

 _…_

 _…_

 _Carnivore._

* * *

Tsuna watched with growing apprehension Kyouya – that had almost destroyed an amusement park – strode in his office, envelope in hand. Reborn arched a brow under the fedora when the Cloud offered the item to him.

"Carnivore."

The hitman took it and Kyouya left. The brunette face-palmed. Even his Cloud? Even him couldn't succeed? That was… unprecedented.

"Dame-Tsuna."

He looked up. Reborn was reading through the paper with strangely blank eyes. He locked gazes with Tsuna, that forced a sudden lump down his throat with a gulp.

The hitman lifted it and waved it in the air slightly, standing and going to the door. "If I fail, no one will be able to do it."

What scared him the most was not that the mission could be reported as a complete failure to Nono, but the fact that _Reborn_ wasn't already marking it as a success… The World's Greatest Hitman was not sure he could do it.

* * *

 _No wonder they all failed. This is useless._

 _…_

 _Fine, here goes nothing…_

 _Took me years._

* * *

Tsuna let out a heavy sigh as he finished taking a shower in his bathroom. He hooked a white towel at his waist and went to his bedroom, brushing another on his wet hair. With a huff, he flopped on his bed, facing the ceiling. His arms fell on the mattress, over his head.

It had already been a week since Reborn had taken up the mission. A week in which his Guardians had behaved even more strangely. Hayato had kept giving him the puppy sad eyes whenever they met. Takeshi had called on a movie night to cheer him up. Lambo had given him a candy bag – heresy. Ryohei had _kindly asked_ for a training fight. Nagi had brought him more snacks and refreshment than usual while he dealt with paperwork. Mukuro had kept appearing out of nowhere, observing him with a scowl, though soft. Kyouya had forced him to a fight a day.

Also, his father had come two days prior to ask about that mission. Knowing Reborn was taking care of it had thrown him off, but satisfied him for the time being. How come everyone knew minus himself? This was starting to stink.

A sudden knock at his door made him sat up, his hair's towel forgotten on the bed. He didn't have time to talk as the door opened and Reborn came through, locking it behind him. Tsuna felt the blush all over his body.

"Wha–Reborn!"

"Yes, that's me."

He tried, but failed, to get the bedsheet to cover himself. He ignored how that dark voice had sent a shiver down his spine. The hitman was in front of him in seconds.

"What are you doi–"

"I succeeded."

A weight he didn't know he had on his shoulders and chest was immediately lifted. "Really?"

Reborn scoffed, then took something from his pants' pocket. "Give me your left hand."

Tsuna obeyed. The man gently ran his fingers on his palm, making him tremble, and rotated his wrist so that the back was facing up. He then picked his ring finger and made something slip on it. The brunette blinked at the simple silver band, then eyed Reborn.

"I don't understand…"

The man took the paper and unfolded it in front of him. "Read it."

He grabbed it and slowly let the words drift into his mind.

 _Dear Tsunayoshi,_

 _Forgive me for this, but there is one last thing I need to be sure of before being finally peaceful for you have everything you may need. You have your Guardians, splendid people that care for you deeply. You have your family, that cherishes you and your kindness. You have a solid future with Vongola, leading it to its original path… But you still lack something of the utmost importance._

 _Don't you feel an empty space in your heart? I felt the same before meeting my late wife. It's a feeling you don't know if you don't experience it first-hand, so I'm giving you this mission: find your significant other. Live happily with her or him, have children, go on. This is my last request, dear boy._

 _Truly Yours, Timoteo_

Tsuna blinked, his eyes moving from the letter to the thin band on his ring finger, to Reborn, as his cheeks felt hot again. The man's left hand was lifted, back to Tsuna, a band like his own glimmering in the dim light of his bedroom.

Swallowing, the brunette locked gazes with his tutor. "Since when?"

Reborn smirked. "Since when what, Dame-Tsuna?"

"Since when did you know I…"

"The beginning."

"And you?"

The hitman huffed. "I didn't want to act on it, wanted to give you another choice… But I, like your Guardians, couldn't find anyone that suited you… Nor that I could tolerate."

Tsuna's lips stretched into a small smile. "Jealous?"

Reborn scowled. It was an answer enough.

"So… you go and put a ring on me, without even asking?"

Tsuna could only shriek when he was suddenly pushed down on the bed and found Reborn looming over him. "I'm staking a claim here, Dame-Tsuna. You let me put it, didn't you?"

"T-technical–"

Two demanding lips stopped his retort. His brain short-circuited, the meaning of what was happening finally dawning. Reborn, the one he'd had a crush on since high school, was kissing him. He had just put a damn ring on his finger! And there was a twin one on the man's finger, too!

Reborn's lips moved against his own, fedora rolling down on the bed. "You're not dreaming, Tsuna. So overcome your shock and understand you're mine now." Teeth closed on his neck and the brunette gasped. "And we're marrying in two years at most."

Wait–WHAT?! MARRYING?!

"You heard me."

Hot breath ghosted on his skin and he could barely talk without panting. "This… This is going fast, Reborn…"

"Bear with it. We've lost a lot of time already. You know I'm not doing this any other way."

Tsuna chuckled despite his position, lifting his hands to the other's shoulders and caressing his neck. "Yes… I know." He brought him down for a brief, sweet exchange. "I think I love you, Reborn." The hitman stopped, head almost hidden in the crook of his neck. "I've liked you for years, but now…" He kissed his cheek. "I think I can say safely that I love you."

Silent moments passed, Tsuna was a beat away from starting to regret saying it. But then, Reborn took hold of his wrists and pinned him down. His eyes were a vortex that the brunette had learned long ago how to decipher. He smiled softly, knowing the answer to his confession was there, in the black orbs staring down at him, with love.

When the rough but gentle lips were lowered again on his own, Tsuna closed his eyes and answered the kiss, giving Reborn the lead, the choice, himself. And Reborn gave him everything back tenfold with care, sweetness, love and passion.

* * *

"I must say I'm surprised, Tsunayoshi. This is not the outcome I expected."

"But your mission has been completed successfully, right?" Tsuna winked at his Cloud, that was leaning on the doorframe with crossed hands. "By Kyouya, nonetheless."

Vongola Nono chuckled, drinking his tea. "I guess… Does everyone know?"

"Well, I have a ring on my ring finger, and Reborn has its twin. Also, he wouldn't let me hide it and he's putting up with my father."

"How did he react?"

"Like a gaping fish, then fainted. When he came to, he demanded a 'honour fight for his son's hand'. He lost, so he's brooding somewhere. My mother took it with glee, on the other hand."

"And your Guardians?"

"They… expected it, I think, though Mukuro keeps showing up when I want him the less."

Another chuckle. "I see you're happy, my boy."

Tsuna smiled softly, looking out of the window to the garden, where his sexy fiancé was training Lambo and Ryohei. "Yes, Vongola Nono." Reborn looked up at him and smirked. "I'm happy."

* * *

 **Thanks for reading! See ya!**


End file.
